I've been gradually stocking my 250-litre tank. I've now got 7 rosy tetras, 7 black neons, 6 dwarf neon rainbows and 5 panda cories. My fish don't school. They are all over the tank and swim with all of the other fish. Sometimes a few will be together, but they don't form a single group of their own type. Is this usual? Do they only school when there is some sort of threat?

My pandas were independent in the smaller tank they used to be in, but they are all over the big tank, they don't hang out together in a group. I thought they needed a group to feel secure? They seem happy to be on their own and some distance from the others.

Thanks kitten. No, they obviously aren't stressed at all. Everyone swims up to everyone and doesn't seem to care what sort of fish they are interacting with. The rosy tetras are a bit shy, they tend to swim up the back more than the others, but the others are all over the place. It just seems odd that they don't stick to their groups as I'd read they needed to do.

Thanks kitten. No, they obviously aren't stressed at all. Everyone swims up to everyone and doesn't seem to care what sort of fish they are interacting with. The rosy tetras are a bit shy, they tend to swim up the back more than the others, but the others are all over the place. It just seems odd that they don't stick to their groups as I'd read they needed to do.

LOL Yeah, that is what is happening in my tank too and I have fish that are not supposed to get along with each other. My Guppies swim up to the Gourami and wag their tails in her face like they are totally comfy. My barbs pair up on occasion but I don't think they feel threatened, they are usually just racing around at that point and wrestling. Tiger Barb, face fighting from the look of it. lol Just reminds me of a bunch of teenage boys.

There is a difference between "schooling" and "shoaling." Freshwater fish are shoaling; marine fish tend to be schooling. We frequently use "schooling" but with respect to freshwater "shoaling" is better.

Shoaling means the fish live together in (usually) large groups of several hundred of the species. As kitten mentioned, when frightened/threatened in the wild, the group will tighten for protection. But in general they tend to remain in their large groups in the wild.

In the aquarium some fish retain this characteristic. Rasbora are excellent shoaling fish that will almost always be together. Among the characins, some do and some don't. The rummynose among tetra are one of the best; cardinals usually but not always. Hatchetfish tend to remain in groups. Some pencilfish species spend most of their time together in a swimming group, but other species spread out.

The main thing is having several fish of the species together. The fish will be considerably more relaxed, less stress--and thus healthier. I have observed over the years that when a group of shoaling fish are introduced to an aquarium, if there is already a group of that species the new ones settle in almost within minutes, regaining their colouration, swimming with the others, generally acting "normal". Whereas on their own, they take longer. This is obvious proof of the effect of larger groups, and is why keeping "shoaling" fish in groups of 6 or more is always recommended.

The aquarist is one who must learn the ways of the biologist, the chemist, and the veterinarian.[unknown source]

Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If you’re going to take it under your wing then you’re responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]

I used to have 12 tiger barbs with my large JD and they would always stay in a shoal. I think this was because they were scared of the JD. once the Jack Dempsey got bigger, they slowly disappeared, now there are none.

and is why keeping "shoaling" fish in groups of 6 or more is always recommended.

I thought all of the fish I have were supposed to be shoaling. I've got 7 of each of my tetras, 6 dwarf neons and 5 pandas but none of them seem concerned about being out of their groups. The rosy tetras seem the most "groupy" but the rest are just spread out all over the tank. Are the tetras supposed to be shoaling (I thought they were), or are the ones I've got not so "groupy"?

I thought all of the fish I have were supposed to be shoaling. I've got 7 of each of my tetras, 6 dwarf neons and 5 pandas but none of them seem concerned about being out of their groups. The rosy tetras seem the most "groupy" but the rest are just spread out all over the tank. Are the tetras supposed to be shoaling (I thought they were), or are the ones I've got not so "groupy"?With good reason, if they all ended up eaten!

As Byron has noted, In the wild,, these shoaling species Shoal,or school if you will in the hundreds,perhaps thousands. They often do so for protection, it is much more difficult for predatory fish to single out one or two fishes in this way, and the shoaling or schooling fishes ,have many sets of eyes on the lookout for such predators as opposed to just three or four sets of eyes.
The minimum numbers suggested for these fishes in aquariums are just that,,minimum. They are much more likely to shoal in larger numbers but tanks should be able to support such numbers and maint should be performed accordingly. (more fish,more pollutant's from food/waste).
In an aquarium with little threat of predators, the fishes feel more secure and there is less need for shoaling.
They will explore all regions of the tank, but you may observe that of an evening ,,and just before light's on of a morning,,that the fishes will be in tight groups for they feel safer in numbers while resting/ sleeping.
Yet other species,,will nearly always travel in groups. Smaller the fish,,the more likely to shoal in my expierience. But agian,, If there is no threat perceived,and plenty of cover in the form of plants real,,or artificial,,, the fishes will be more comfortable and will explore all regions, and only travel in tight groups on occasion.
Have also observed that smaller fish seem to shoal more so in larger aquariums ,as opposed to smaller ones.
When traveling the length of large tanks,,they feel safer doing so in groups.
Just some of my observations.